Thread: Case head separation imminent

Originally Posted by Cigar

This bit isn't quite correct, what you are referring to is excessive headspace. Headspace is the area from the boltface to the shoulder (rimless cartridges, e.g. 308), the front of the rim (rimmed cartridges e.g. 30-30) or the front of the belt (belted magnums, e.g. 7mm rem mag).
Attachment 209386

That is how it is measured yes, but the headspace is the amount of clearance between the cartridge and chamber dimensions.